The pursuit of high accuracy has been the cornerstone of Grand Seiko’s values since its first watch was created in 1960. In the late 1970s, the development of Spring Drive began with an aim to harmoniously blend the traditional energy of a mainspring with state-of-the-art electronic watchmaking advancements. In 2004, Grand Seiko introduced the Spring Drive Caliber 9R65 with a monthly rate of ±15 seconds.
Today, this legacy of accuracy in watchmaking reaches new heights with the announcement of the Spring Drive Caliber 9RB2, which receives the new U.F.A. designation, standing for “Ultra Fine Accuracy.” The groundbreaking movement boasts a level of precision defined not by accuracy in seconds per day, week, or month, but by its accuracy over one year. The automatic U.F.A. movement has an astounding annual rate of ±20 seconds, making it the most accurate wristwatch movement powered by a mainspring today.*
*As of April 2025, based on Grand Seiko’s research.
In 2025, the Caliber 9RB2 makes its debut in the Evolution 9 Collection. To the east of the Shinshu Watch Studio lie the Kirigamine Highlands, where frost-covered trees can be observed during harsh winter months. The intricately textured dial captures the beauty of these ice forests thanks to finishing techniques that create pale blue tones that are subtle yet striking in their presence.
Dial inspired by the ice forests
The dial with pressed pattern inspired by the beauty of ice forests has a silver-tinged blue hue, evoking the ice forests seen through crisp, clear air, and is beautifully accented by a tempered blue seconds hand. Thanks to the movement’s compact design, the new watches have a case diameter of just 37mm, making them the smallest models powered by the 9R series to date and ideal for smaller wrists.
Astonishing accuracy
The new movement achieves its ±20-seconds-per-year accuracy thanks to new and enhanced manufacturing and processing methods for the three-month-aged quartz oscillator, and a newly designed IC. And, as with the 9RA series of Spring Drive movements, the frequency of each individual quartz oscillator is measured at several different temperatures, with the resulting data necessary for thermo-compensation programmed into the low-power IC.
Both the oscillator and sensor are vacuum-sealed to minimize temperature differences and protect against external factors such as humidity, static electricity, and light, ensuring precise temperature adjustments and the stable performance of the quartz oscillator. In addition, for the first time in Spring Drive, the new movement features a regulation switch that can be used during after-sales service to correct any divergences in accuracy that may occur over long periods of use.
Movement finishing reflecting the natural beauty of Shinshu
The movement's beauty is revealed through the sapphire crystal case back, with mirror-polished, beveled edges adding brilliance. Its design, inspired by the natural surroundings of the Shinshu Watch Studio where it is made, reflects a uniquely Japanese aesthetic characterized by understated charm and elegance.
The jewels echo the glittering stars that sparkle during the early days of winter above the surrounding mountains, and the delicate texture of the movement’s surfaces reflects the frost that winter brings to the trees of Shinshu, where all Grand Seiko Spring Drive watches are made.
The Spring Drive U.F.A. caliber with an astounding annual rate
The pursuit of high accuracy has always been the cornerstone of Grand Seiko’s values. Receiving the new U.F.A. designation, which stands for “Ultra Fine Accuracy,” Caliber 9RB2 boasts a level of precision defined not by accuracy in seconds per day, week, or month, but by accuracy over one year. The movement has an astounding annual rate of ±20 seconds, or approximately ±3 seconds per month.
